So by itself it's going to be a +1 damage, however, with additional bonuses of: Strength Implant, Juggernaut, Heavy Hitter (penetration is nice to have), and on top of the bonuses you'll be getting from your base Str. You're going to be hitting those delicious high damage thresholds with melee. Colony Ship's minimal bonuses don't look sexy by themselves, but when you stack them on top of each other, things get nuts.
If you get Utility Bar, or any other light weight weapon (weapons that have low AP costs basically), and spam fast attacks. You'll do lots of damage. Also you can still stagger. Heavy Hitter gives bonuses towards it. As do weapons as well. Losing aimed attacks doesn't prevent you from staggering enemies.
Also one very important bit. Faythe can use her guns to proc aimed attack effects. So you're not completely losing those either.